The hack has since been fixed. These are some of the tweets that were affected:

Mashable says it received an email on Monday from an account believed to belong to the SEA:

"[The] group notified us of the hack, but would not provide details about how it accomplished it. It appears the SEA did not actually access Obama's social media accounts, but altered the links in the posts by tampering with the URL shortener service for BarackObama.com."

The Syrian Electronic Army claimed responsibility for a series of attacks in August, which hit NPR.org, The New York Times, The Washington Post and others.